Expert: Don Berlan - 6/24/2010

Question
Hi Don . Hope you can help! I've got a 1986 325i bmw.It starts with no problem when it is cold . Once i Drive with it and it gets hot , it will also start with no problem if I switch it of and start again. But the moment it is hot and I leave it for about 15min , it refuse to start. I have to push her or leave her to cool off completely before she starts. The following where tested and no problems there . Coil, starter, battery . Any idea what could cause this? A guy I met said there is a fuse/relay that sometimes can give issues. but have no clue where to look for this fuse/relay.

Kind regards ,Richard

Answer
Checking the thermo time switch(the sensor that is brown on the thermostat housing)is where I would start.When cold it allows the cold start valve to spray fuel for starting(that sensor is on the intake,top of the intake)Check all your grounds from the battery that are bolted on the body,a ground that is often missed.